http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Guizhen Li,Tao Zhu,Yingjie Lei 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.10
A series of deep eutectic solvents (DESs) were prepared using glycerol and choline chloride (ChCl), and Fourier transform infrared spectrometer (FT-IR) was used to analyze the spectra of glycerol, choline chloride and DESs based on glycerol and choline chloride. Then DESs were used as the additives of mobile phase to optimize chromatographic behavior of caffeic acid in high performance liquid chromatography (HPLC). A 17-run Box-Behnken design (BBD) was employed to evaluate effect of DESs as additives by analyzing the maximum theoretical plate number. Three factors, reaction temperature (60 oC, 80 oC, 100 oC), molar ratio of glycerol and choline chloride (2 : 1, 3 : 1, 4 : 1, n/n), and volume percent of additives (0.05%, 0.10%, 0.15%, v/v), were investigated in BBD. The optimum experiment condition was that of reaction temperature (80 oC), molar ratio of glycerol and ChCl (3 : 1, n/n), and volume percent of additive (0.10%, v/v). The mean chromatographic theoretical plate number of the caffeic acid this condition was 1567.5, and DESs as additives shorten the retention time and modify the chromatogram shape, proving DESs as additives for effective theoretical plate number and column efficiency in HPLC.
Tannic Acid and Ferrous Sulfate Modified Kapok Fiber for Oil-water Separation
Guizhen Ke,Shuhui Chen,Jiani Tang,Huanmin Li,Keshuai Liu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.11
Biodegradable oil absorbing materials have attracted extensive attention in dealing with oil spill pollution. Todevelop more excellent oleophilic oil sorbent, the combination of tannic acid and ferrous sulfate was employed to treat therenewable and biodegradable natural kapok fiber. The as-prepared kapok showed superhydrophobic characteristics with highwater contact for the formation of tannic acid and ferrous ion complex on kapok surface, which was confirmed by scanningelectron microscopy observation and infrared spectroscopy and X-ray diffraction analysis. The preparation process of themodified kapok fiber was optimized. When the sodium chlorite pretreated kapok fiber was firstly treated with 4.25 g/l tannicacid and subsequently immersed in 4.25 g/l tannic acid and 6.25 g/l ferrous sulfate mixture at 60 °C for 15 min, the aspreparedkapok fiber presented the best oil absorption capacity and hydrophobicity (water contact angle 150.7 °). The treatedkapok had good adsorption capacity for oils and organic solvents, 48.2, 41.6, 53.4, 52.8, 49.2, 41.2 g/g for vegetable oil,diesel oil, silicone oil, carbon tetrachloride, DMF and n-hexane, respectively. In addition, the tannic acid and ferrous sulfatetreated kapok was recycled for six times through simple mechanical squeezing, and showed good oil-water separationperformance oil, indicating its potential application in the removal of spilled oil on water.
A Comparative Study of the Social Security System between China and Korea
Guizhen Heng,Jing Li Liu,장세철 한국비교정부학회 2009 한국비교정부학보 Vol.13 No.2
With the continuous development of economy and the improvement of social progress, most countries in the world establish a more comprehensive social security system and continuously improve its functions. Improving social security system is one of the most important problems that China as a socialist country has to solve urgently at present and it is also a guarantee of building a harmonious socialist society. The social security system in the newly industrialized country, South Korea, especially deserves our attention. We should also see that due to the difference of the productivity level of development, financial and economic strength, population and resources the social security system behave divercitily some of the institutional framework and policy system of referential significance to us. This article thinks that if China can learn such experiences from South Korea as legislature first, avoiding a financial crisis, the focus on protection, making full use of the family security features, etc., then they can play a positive role in promoting the improvement of China's social security system.
Xiaoqin Wang,Guizhen Li,노경호 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.2
A novel deep eutectic solvent (DES) and ionic liquid (IL)-modified graphene (G) and graphene oxide (GO) were synthesized and used as effective adsorbents for the preconcentration of three chlorophenols (CPs), 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP), and 2,4,6-trichlorophenol (2,4,6-TCP), in environmental water samples prior to high-performance liquid chromatography (HPLC). The new materials were characterized by scanning electron microscopy (S-4200) and Fourier-transform infrared spectrometry. The prepared functionalized GO@silica shows remarkable adsorption capacity toward CPs. When used as solid-phase extraction (SPE) sorbents, a superior recovery (88.49–89.70%) could be obtained compared to commercial sorbents, such as silica and aminosilica. Based on this, a method for the analysis of CPs in water samples was established by coupling SPE with HPLC. These results highlight the potential new role of DES and IL-modified GO in the preparation of analytical samples.
Extraction of Quercetin from Ginkgo biloba by DESs-based Monolithic Cartridge with RP-HPLC
( Wang Xiaoqin ),( Li Guizhen ),노경호 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1
Deep eutectic solvents (DES) were synthesized with choline chloride (ChCl), template molecular monolithic (TMM) and non-DES monolithic (N-DES-M) without template, were prepared in an identical procedure. Fourier transform infrared spectrometer (FT-IR) and field emission scanning electron microscopy (FE-SEM) were used to characterize the obtained polymers. Rebinding experiment and solid-phase extraction (SPE) were used to prove the high selectivity adsorption properties of the polymers. The optimum extraction condition was found to be: ultrasonic time optimized (30 min), the volume fraction of ethanol and ratio of liquid to material (20 mL g-1). Under these conditions, the extraction yield of quercetin was 290.8 mg g-1. Purification of Ginkgo biloba extract was achieved by SPE process. The results showed DES-sbased monolithic cartridge had potential for promising functional adsorption material for the purification of bioactive compounds.
LIST EDGE AND LIST TOTAL COLORINGS OF PLANAR GRAPHS WITHOUT 6-CYCLES WITH CHORD
Aijun Dong,Guizhen Liu,Guojun Li 대한수학회 2012 대한수학회보 Vol.49 No.2
Giving a planar graph G, let $x^'_l(G)$ and $x^{''}_l(G)$ denote the list edge chromatic number and list total chromatic number of G respectively. It is proved that if a planar graph G without 6-cycles with chord, then $x^'_l(G){\leq}{\Delta}(G)+1$ and $x^{''}_l(G){\leq}{\Delta}(G)+2$ where ${\Delta}(G){\geq}6$.